当前位置: 首页 > 网络学院 >

PowerShell实现统计函数嵌套深度

新客网 XKER.COM 时间:2015-06-03 08:50:28  评论:

当你调用某个函数时,PowerShell会增加一次嵌套层次。当一个函数调用了另一个函数,或着脚本,也会增加嵌套层次。今天分享一个函数,它能告诉你的脚本嵌套的层次:

function Test-NestLevel
{
$i = 1
$ok = $true
do
{
try
{
$test = Get-Variable -Name Host -Scope $i
}
catch
{
$ok = $false
}
$i++
} While ($ok)
 
$i
}

当你调用的函数具有递归调用时,上面的函数非常有用,来看一个调用的示例:

function Test-Diving
{
param($Depth)
 
if ($Depth -gt 10) { return }
 
"Diving deeper to $Depth meters..."
 
$currentDepth = Test-NestLevel
"calculated depth: $currentDepth"
 
Test-Diving -depth ($Depth+1)
}
 
Test-Diving -depth 1
 


当你运行Test-Diving时,函数会调用自己10次。函数使用一个参数来控制嵌套层次,而Test-NestLevel负责返回确切的深度数。

注意这里有个区别:Test-NestLevel返回绝对的嵌套层次,参数会纪录这个函数调用自己多少次。如果Test-Diving被嵌入到另外一个函数中,绝对深度和相对深度会不同。


PS C:\> Test-Diving -Depth 1
diving deeper to 1 meters...
calculated depth: 1
diving deeper to 2 meters...
calculated depth: 2
diving deeper to 3 meters...
calculated depth: 3
diving deeper to 4 meters...
calculated depth: 4
diving deeper to 5 meters...
calculated depth: 5
diving deeper to 6 meters...
calculated depth: 6
diving deeper to 7 meters...
calculated depth: 7
diving deeper to 8 meters...
calculated depth: 8
diving deeper to 9 meters...
calculated depth: 9
diving deeper to 10 meters...
calculated depth: 10
 
PS C:\> & { Test-Diving -Depth 1 }
diving deeper to 1 meters...
calculated depth: 2
diving deeper to 2 meters...
calculated depth: 3
diving deeper to 3 meters...
calculated depth: 4
diving deeper to 4 meters...
calculated depth: 5
diving deeper to 5 meters...
calculated depth: 6
diving deeper to 6 meters...
calculated depth: 7
diving deeper to 7 meters...
calculated depth: 8
diving deeper to 8 meters...
calculated depth: 9
diving deeper to 9 meters...
calculated depth: 10
diving deeper to 10 meters...
calculated depth: 11
 
PS C:\>


Test-NestLevel总会返回从当前代码的作用域到全局作用域的嵌套深度。

如果您喜欢本文请分享给您的好友,谢谢!

评论列表(网友评论仅供网友表达个人看法,并不表明本站同意其观点或证实其描述)